Self-locking flush latch



July 26, 1949. M. P. WRIGHT 2,477,472

sELF-LocKNG FLUSH LATCH Filed Feb. 2l; 1947 2 Sheets-Sheet 1 l Jlvlly 26, 1949. M, P, wRlGHT 2,477,472

SELF-LOCKING FLUSH LATCH Filed Feb. 21, 1947 2 sheets-sheet 2 INVEN TOR.

W Mam.

ure 1, and hence prevent releasing movement of the toggle lever I6 which would occasion such shifting movement of the trigger.

To overcome this positive lockingA of the toggle in the closed or holding position, the locking lugs 30 must be lifted out of the locking notches 3l. This can be readily eected by one familiar with the action by simply pressing inward on the free end of the trigger, against the tension of the spring arms 29, as in Figure 3. "i

After unlocking theA toggle, continued pressure on thetrigger plate will Acause'it to engage the outer end Wall 20 of the toggle lever to rock the same past dead center and into the hook releasmg positions indicated in Figures 4 and 7.

In the extreme position shown in Figure 7, the upper edgeof the end wall 20 of the toggle lever engages over the top of the hook to positively force the same downward clear of the rod or other holding abutment I2=v d In carrying Vover, to the unlocked position, the inner ends of the lever. and tl'ie trigger svvingr outward through the opening 24, 25, rendering them accessible for fully controlled d operation of the latch both for releasing and for restoringrpurposes., In the Figure `7 position, the toggle level1 holds the hookdown so as to be clear of tlie cooperating abutment I2 when the cowling or other separated member is returned to position. 'Then when the separated parts are correctly disposed,

the swinging of the togglelever back in the returnv direction will, through the spring 21, throw the hook up into engagement With abutment I2 automatically effecting 4therequired coupling.

,Continued movement of thetoggle lever and trigger will carry the h ook center I5 past the lever center I'I,to,lock the toggle and the toggle will then be positively secured in this relation by the outstandinglocking lugs30 von the trigger dropping into the locking notches 3 I in the mounting bracket. .The latch will thus be secured against vibration or other forces tending to shift thetoggle leverl in Athe releasing direction. Au-

thorized unlocking and release of the toggle, how-V Votherrthan illustrated, the only requirement being that they interlock with a hooking action so that with the closing operationof the toggle, they will be eiectiveto pull the relatively separable members 9 and I0 together or toward each other.

What is claimed is:

1. A self-lockingfilush latch comprising a base having. an openingtherethrough, a toggle lever pivoted on said base over said opening, a securing hook` having apivotal connection with said toggle lever arranged to. pass. a dead centerf relation in;

4 respect to the pivotal mounting of said toggle lever to effect the securing of the latch in closed condition, a trigger lever pivotally connected with the toggle lever on a center at the opposite side of the pivotal mounting of said lever from the pivotal connection of theI securing hook thereto, said trigger being disposed in said opening in the base toiorm a closure thereto in the securing position o the toggle lever and a locking lug on said trigger having interlocking engagement with said base to prevent accidental releasing movement of the toggle lever in said position of the parts.

2. A self-locking flush latch comprising a base having an opening therethrough, a toggle lever pivoted on said base over said opening, a secur-V ing hook .havingV a pivotal connection with said toggle lever arranged to pass a dead center relation in respect to the pivotal mounting of said toggle lever to eiect the securing of the latch in closed condition, a trigger lever pivotally connected with the toggle lever on a center at the opposite side of the plvotal'mounting of said lever from the pivotal connection oi the securing hook thereto, said triggerbeing disposed in said opening in the base to form a closure thereto in the securing position of ythe toggle lever and a locking lug on said triggerhaving interlocking engagement with said base to prevent accidental releasing movement of the toggle lever in said position of the parts, said base having a seat disposed to receive said locking lug 'm said securing position of the toggle levenand to then oppose rocking movement of the ltoggle lever in the releasing direction4 and said trigger having free movement about the center of pivotal connection with thev toggle lever sufcient to carry said locking lug out of said seat.

3. A self-locking flush latch comprising a base having an opening therethrough, a toggle leverY pivoted on said base over said opening, a securing hook having a pivotal connection with said togglev lever arranged to pass a dead center relation in respect to the pivotal mounting of said toggle.

lever to effect the securing of the latch in closed condition, a trigger lever pivotally connected with thetoggle lever on a center at the opposite side and to then oppose rocking movement ofA the'togi gle lever in the releasing direction and said trigger having free movement about .the center of pivotal connection with. the'toggle lever suicient to carry said locking lug out of said seat and said! toggle lever having an abutment in the path of said unlocking movement of the trigger and whereby said toggle lever may be shiftedin the releasing direction by said trigger as avcontinuation of said unlocking movement,

Y 4.. A self-locking flush latch comprising a base having an opening therethrough, a toggle lever' pivoted onsaid base over said opening, a securing hook havinga pivotal connection with said toggle lever arranged to pass a dead center-relation inV respect to the pivotal mountingvof said toggle lever to effect the securing of theV latch in closed aoiisthewpivotaly mounting of saidgleveri froml the .pivotal .connection ofl the securing hook'thereto, said trigger being disposed in said openinginfthe .ibase to `form a closure thereto inthe securing :position of the` toggle lever and a locking lug `on r:said trigger having interlocking engagement with 'said base to prevent accidental releasing moveement` of the toggle lever in said position ol the parts, said base having a seat disposed to .receive `esaidlocking lugiinsaid securing position ofthe .toggle lever .and to `then opposite rocking move- .mentor theitoggle lever in the releasing direction `andsaid trigger having free .movement aboutthe ,center of pivotal connection with` the togglelever suicientto carry` said lookingllug out of said seat =anclsaidtoggle lever having an abutment in the path of said unlocking movement ofthe trigger -anduwhereby. said toggle lever may be shifted in .fthefreleasing direction by said trigger as a con- ;.ti'nuation of said unlocking movement and a `spring yieldingly holding said `trigger in the lock- :ing position of the same closing said `openingin .'-the base.

5. A self-locking nosh latch comprising a base having an opening therethrough, a toggle lever npivoted on said `base over said opening, a securing yhook having a` `pivotal connection with said toggle `:leverarranged `to passa dead center relation in `respect to the `pivotal mounting` of said toggle .lever to effect the securing of the latch in closed condition, a trigger lever pivotally connected with the toggle lever on a center `at the opposite side of the pivotal mounting of said lever from the `pivotal connection of the securing hook thereto, -said trigger being disposed in said opening in the baseto form a closure thereto in the `securing .position of the toggle lever and a locking lug on said trigger having interlocking engagement with said `.base to prevent accidental releasing move- -ment` of the .toggle leverin `said position of the parts and an expansionspring acting in opposite directions against said securing hook and `said trigger. i

6. A latch for connecting relatively separable members and comprising a toggle unit for mounting on one member for engagement with a keeper element on the other member, said tOggle unit comprising a pivotally supported toggle lever, a hook for engagement with the keeper element, saidthook being pivotallf,r connected with `said toggle lever at one side of the center of `pivotal support of `said lever, a` trigger pivotally connected with said lever at the opposite side of said center of pivotal support and means for locking said trigger in position to oppose pivotal movement of the toggle lever in the latch releasing direction and including a stationary member and a locking element on the trigger engageable with said stationary member, said trigger having a free swinging movement about the center of pivotal connection with the toggle lever in a direction to carry said locking element out of interlocking engagement with said stationary member and into engagement with the toggle lever in the latch releasing direction of movement of the latter and whereby said trigger may be swung first to unlock it and then to rock the toggle lever in the latch releasing direction 7. A latch for connecting relatively separable members and comprising a toggle unit for mounting on one member for engagement with a keeper element on the other member, said toggle unit comprising a pivotally supported toggle lever, a hook for engagement with the keeper element, said hook being pivotally connected with said iso `t'mggle `:levers-at one side of the center of. .pivotal :support ,of said .leven a triggerpivotally con- `nectecl.-withsaid lever atthe oppositeside of said :center ofpivotal support, meansior locking `said trigger-.inl position to :oppose pivotal. movement of :the toggleslever in fthe latch `releasing direction .and including astationary. member and a locking relement `on thetrigger engageablefwith saidsta- .tionary member., said. triggerhaving a free swing- Sing movement about the center of pivotal connec- :tionxwith theutoggle lever in a 'direction tocarry .said locking element` outof `interlocking `engage- .mentwith said stationary member and into engagement with :the :toggle .lever in the latch-re leasing directionof movement of the lattervand `a spring` for yieldingly holding said triggerLin `position away fromqtheitoggle lever to interlock Awith saidrstationarymember. i

v8. Alatch `forconnectingrelatively separable :members .and comprising a toggleunit formount- .ing on one member for engagement with Yakeeper :toggle'lever inthe latchreleasing` direction and including astationary memberand a locking Vele- Iment on the` triggerengageable with saidstation- `ary member, Vsaid .trigger having a free swinging kmovement about the center cfpivotal connection witnthetogglelever in a directionto-carry said locking element out of interlocking engagement with said stationary `member Aand` into lengage- -ment with `the toggleleverinthe latch releasing direction of movement of the latter and a spring .coiled aboutsaid `pivotal connection-of the securing hookand bearing at one end against said :hook "and atlthe opposite end against said trigger itourge said .hook toward the keeper element and ltofyieldinglythr-ust.the trigger into interlocked engagement` with the stationary-member.

9. A latch of the character disclosed compris- Iing a lpivotally mounted yoke leverclosedat one endland open through the opposite end-,-said lever being-.pivotally'mounted between its ends, a securinghookpivoted at one end withinthe closed end ofthe-yoke lever and free to swing throughthe open end of the yoke lever, a trigger pivoted at one end to the open end of the yoke lever, a locking element on said trigger lever and a stationary member for interlocking connection with said locking element in position to secure the yoke lever against movement.

10. A latch of the character disclosed comprising a pivotally mounted yoke lever closed at one end and open through the opposite end, said lever being pivotally mounted between its ends, a securing hook pivoted at one end within the closed end of the yoke lever and free to swing through the open end of the yoke lever, a trigger pivoted at one end to the open end of the yoke lever, a lockingeleinent on said trigger lever, a stationary member for interlocking connection with said locking element in position to secure the yoke lever against movement and spring means interposed between said yoke lever and trigger for yieldingly holding the latter in position to interlock with said stationary member.

11v A latch for connecting relatively separable members' and comprising a toggle unit for mounting on one memberY for engagement with a keeper element on the other member, said toggle unit comprising a pivotally supported toggle lever, a hook :for engagement with the keeper element, said hook being pivotally connected with said toggle lever'at one side of the center -of pivotal tionary member, said trigger having a free swingf ing movement about the center of pivotal connection with the toggle lever in a direction to carry said locking element out of interlocking engagement with said stationary member and into engagement with the toggle lever in the latch i, releasing direction of vmovement of the latter and a spring for yieldingly holding said trigger in position to interlock with said stationary member, said toggle lever having an abutment engageable with the back of the hook in the full releasing movement of the toggle lever to shift said hook against the tension of said spring clear of engagement with said keeper element.

12. A self-locking, pull-in flush latch comprising companion hook and abutment elements,V a toggle lever pivotally supported intermediate its ends, said hook element being pivotally connected with one end of said toggle lever andsaid toggle lever having a range of travel to carry the pivotal point of connection of the hook element to oppo- Jsite sides of the dead center position of the pivotal mounting of the toggle lever, a trigger pivoted at one end to the opposite end of the toggle lever and extended past the pivotal center of the toggle lever to a position adjacent the hook pivot end of the toggle levei` for applying pressure to the latter end to swing the toggle in the hook releasing direction and mounting means for said toggle lever, said mounting means having an opening and said trigger closing said opening in ush relation to provide flush exposed means 1for actuating the toggle lever. l

13. A self-locking, pull-in flush latch comprising companionk hook and abutment elements, a toggle lever pivotally supported intermediate its ends, said hook element being pivotally connected with one end of said toggle lever and said toggle ilever having a range of travel to carry the pivotal -flush relation to provide ush exposed means for actuating the toggle lever and spring means for yieldingly holding the trigger in said closing position with the free end of the trigger spaced away `from the toggle lever.

14. A self-locking, pull-in ilush latch comprising companion hook and abutment elements, a

. toggle lever pivotally supported intermediate its ends, said hook element being pivotally connected With one end of said toggle lever and said toggle lever having a range of travel to carry the pivotal point of connection of the hook element to opposite sides of the dead center position of the pivotal mounting of the toggle lever, a triggerpivoted at one end to the opposite end of the toggle lever and extended past the pivotal center of the toggle lever to a position adjacent the hook pivot end of the toggle lever for applying pressure to the latter end to swing the toggle in the hook releasing direction, mounting means for said toggle lever, said mounting means having an opening and said trigger closing said opening in ush relation to provide flush exposed means for actuating `the toggle lever, spring means for yieldingly holding the trigger in said closing position with the free end of the trigger spaced away from the toggle lever and toggle lever locking elements on said trigger and mounting means automatically engageable in said closing position of the trigger.

MILO P. WRIGHT.

REFERENCES CITED The following refererrces are of record rin the le of this patent:

UNITED STATES VPA'IIIENTS Number Name Date 1,250,574 Ferris Dec. 18, 1917 Y 2,393,945 Weise V Jan. 29, 1946 

